Wednesday, November 30, 2011

The earthquakes of magnitude 4.5 at Nedumkandam(1988), 4.3 at Wadakkanchery (1994) and the earthquake of magnitudes 5 that occurred in Periyar basin (12-12- 2000) and 24 tremors of 2010 clearly justify the views of seismologists that the seismic activity has recently. The study by IIT Roorkee confirms this. In USA the geological survey uses aircraft with magneto-meters for studying the magnetic anomalies and detect the hidden faults to assess the seismic hazard potential in the selected zones. The continuing work of the dedicated and intelligent earth scientists is helping to protect the lives and properties of citizens in different regions from the earthquakes that are inevitable in the near future. But unfortunately the Indian experts without undertaking such investigations on seismic potential of Mulla Periyar dam are jumping to make unscientific pronouncements on the safety of the dam although such expert opinions are likely to present risks to the life of lakhs of people in Kerala.

The probability of failure of a dam depends on factors like seismicity of the area, spillway capacity, nature of foundations, seismic design quality of construction, feasibility of disaster management, bombing by terrorists or enemy countries. About 10% of the dams failed in India and abroad and about 2% of them are reported to have collapsed. The Vaiont dam in Italy failed in 1963 due to the collapse of the mountain slopes around the reservoir basin due to a series of medium earthquakes. Some dams in the western ghats of Maharashtra and Karnataka have also collapsed. About 2000 dams have been identified by the US experts as unsafe and it is estimated to cost $1000 million to rehabilitate them. Under the dam Safety Acts in USA and Canada, the risk analyses and dam-break scenarios are used as tools to assess the hazard potential of a dam as it provides firstly the data required for scientific estimation of spill way capacity and secondly to predict the flood wave depth and flood wave arrival times for identifying the villages and towns that could be drowned by the flash floods due to the collapse of the dam. Thus flood management in preventive terms means dam safety and in protective terms flood plains management. According to the International Standards (ICOLD –57, Bulletin46) seismic safety of the dam ensures that firstly the dam does not suffer significant damage due to an anticipated earthquake and secondly the damage to the dam is limited and no catastrophic failure occurs leading to uncontrolled release of water due to a maximum credible earthquake.

While studying the Environmental safety of Mulaperiyar dam, two expert committees, one appointed by the Kerala state and another by the union Government presented contradictory recommendations on safety aspects of the dam. A perusal of Newspaper reports on the findings of Expert Committee of the Central Government indicates that the report gives a false impression about the safety of Mulaperiyar dam and naturally the farmers of Tamil Nadu have become suspicious about the genuine grave concerns of Kerala .Safety and Environmental hazards of Mulaperiyar and other dams like Iddukki are questions of life and death to Kerala and such issues are too serious to be blindly left in the hands of Experts since they involve not only the technical but also the major social problems. It is necessary to create proper awareness on this controversial problem so that the people can safeguard their right to life and the environment as envisaged under section 51(A) of the constitution of India.
The experts group of Central Water commission according to Mr.K.Paramesaran Nair alone representative of Kerala Government had floughted the fundamental rules of dam safety. Mr.Nair says that 95% of the water from the Mulaperiyar reservoir is now given to Tamil Nadu which wants the balance of 5% which amounts to 1.2TMC and for this purpose Tamil Nadu demands to raise the height of the dam from the present level of 136ft to 152ft. or even 145ft. and this demand poses threat to the public interests of Kerala. If the height of dam is increased and if an accident occurs to the dam the flash floods will destroy Kumili town and millions of people will perish in four districts downstream of the dam in Kerala state. Besides 10,000 acres of forest land would be submerged and 10,000 tribal families will be deprived of their food and shelter. In addition the region is biodiversity hot spot. This poses a serious threat to the ecosystem and ecological balance. The claim of Tamil Nadu that the dam has enough strength to hold more water is not based on scientific grounds.

The annual leaching from the dam is 30 tons of water per year and cement grouting was done. The Probable Maximum Flood (PMF) used in the design of Mulaperiyar dam was 2495 cumecs and it was revised to 6000 cumecs as suggested by Central Water Commission. Idukki has a PMF of 8000 cumecs and Idukki would not be able to handle a major inflow of 6000 cumecs, if Idukki itself has water upto FRL or near to it. If both the projects are subject to flooding at the same time is pose a threat to the dams that means even if Mulaperiyar does not fail. Since several small rivers while diverted into Idukki subsequent to its completion. The failure of Mulaperiyar dam could be catastrophic for Idukki project. Idukki dam that was built to hold 2000million cubic meters of water (70 TMC) will have to absorb flash floods of 443 million cubic meters (15 TMC) from 50 kms away and if it fails hundreds of towns and villages of Periyar basin in Kerala will be wiped out if the dams of Idukki failed. Idukki was designed for PGAh of 0.05g and PGAv of 0.025g. It means that the dams cannot withstand earthquakes of higher intensity expected in the area in the near future. Lower Periyar dam downstream is designed for PGAh of 0.1g. However landslides in the catchment due to recurring earthquake tremors and intense rains can cause failure of the dams as had happened in the case of Vaiont dam in Italy in 1963. The scientific studies indicating unstable hill slopes and heavy siltation of the reservoirs indicate the hazards waiting in the wings.

Medium earthquakes like the once that occurred in Periyar basin have produced very high Peak Ground Acceleration (PGA) in several Geo-tectonic environs. For instance the Ancona earthquake of 4.6 magnitude in Italy (1972) produced PGA of 0.61 and the Oroville quake in USA (1975) of magnitude 4.6 produced PGA of 0.63 and the Salvador earthquake (1986) of 5.4 magnitude produced a PGA of 0.70 and the Cerro earthquake of USA (1987) of magnitude 5.5 produced a PGA (horizontal) of 1.12g and a vertical PGA of 0.61 and hence the Mulaperiyar dam which was not designed to withstand any earthquake can never be expected to be safe particularly when it is century-old and located in a highly earthquake prone zone.

If the design, construction, operation and maintenance of the project works placed in the hands of Tamil Nadu and the beneficiaries are Tamil farmers of Madurai and the potential victims of the catastrophic failure of the dam are in hundreds of villages and towns of Kerala, it is impossible to preface the risk analysis and Disaster management reports for emergency evacuation of people likely to be killed due to a maximum credible accident to one or more dams on Periyar river. In the absence of these basic reports, the recommendations of the Expert committees appointed by the Central Government to study safety aspects of Mulaperiyar dam become null and void.

Failure of dam also occur due to the following causes:
1.Liquefaction of the materials used in the dam.
2.Liquefaction in the foundation soil
3.Wrong estimation of the peak ground acceleration due to wrong assumptions on seismic potential of the area in terms of magnitude, intensity and methods followed for estimating effective Peak Ground Acceleration
4.Prediction of deformations and stresses from earthquake loading
5.Inability to make necessary modifications in the size of the dam that will provide an acceptable response in case the predicted deformations or stresses are intolerable due to revised increases in seismicity of the area during project construction.
6.Inability to estimate performance of the dam and foundation characteristics by comparison with case histories of dam failures
Other modes of dam failures include:
7.Slope failures induced by ground motions
8.Sliding of the dam on weak foundation materials
9.Disruption of dam by major fault movement in the foundation
10.Loss of freeboard due o differential tectonic movements
11.Loss of freeboard due to slope failures or soil compaction
12.Piping failure through cracks induced by the ground motions
13.Overtopping of dam due to seiche in the reservoir
14.Overtopping of dam due to slides into the reservoir
15.Overtopping of dam due to failure of spillway or failure of dams upstream.

The water level in Periyar was reduced from 152ft. to 136ft. in 1979 due to doubts raised about the strength of the Century-old structure. When American experts are reviewing the safety of all their dams in the light of the latest tremors and are dismantling some old dams, strengthening some weak ones and redesigning some more by reducing their storage levels so that emergency evacuation measures become feasible for implementation during collapses of dams to minimise loss of lives and properties, how can some Indian experts who have no indepth knowledge on seismic safety of dams venture to vouchsafe for the safety of Mulla Periyar dam without making any scientific analysis pertaining to all the above relevant factors as followed in the developed countries in this regard?
The State Government's finding that the Central Water Commission (CWC) underestimated the probable maximum flood (PMF) in Mullaperiyar catchment when it recommended strengthening measures for the dam back in 1979 heightens public concerns about the safety of the dam. (PMF is the flood that can be expected from the most severe combination of critical meteorological and hydrologic conditions that are reasonably possible in a region.) This is something that had not been taken note of by the technical committee of the State when it recommended in the Nineties that the water level in the reservoir should not be allowed beyond 136 feet. Nor had these arguments been presented before the Supreme Court. The key point is that the CWC had recommended a PMF of 6,003 cubic metres per second (cumecs). However, an actual flood in 1943 was of 8,453 cumecs. This means that water will overtop the dam if the maximum possible flood occurs.
Because this is such a crucial safety aspect of the dam, the pattern followed uniformly in all dams in the country is to identify the maximum observed flood that has occurred in the catchment area. Then, this figure is significantly boosted up and the PMF identified from this boosted-up figure.In the case of Mullaperiyar dam, the maximum flood that took place in the reservoir was 8,453 cumecs. However, curiously, for the purpose of determining the PMF, the then Chairman of CWC recommended 7,249 cumecs, a figure lower than this maximum amount. This recommended figure was again lowered for reasons unknown to 6,003 cumecs. Even with this artificially lowered figure, the water will flow over the top of the dam but for the parapets. Not only this but also the siltation in the dam will further contribute to the rising of the mean water level so that water flows over the top of the dam.
While assessing the safety of the dam, the expert committee of the CWC had taken the design horizontal seismic co-efficient as 0.12 g instead of 0.18 g. The value 0.18 g is the least recommended value for zone III as per IS 1893-1984 where Kerala is situated. In this context it may be noted that the standing committee set up by the Union Government for advising the seismic coefficient for the river valley projects recommended a value of 0.24 g. "This extremely low value of 0.12 g has incorrectly made the dam `safe' for water level up to 142 ft. This action of the expert committee is against the guidelines published by the CWC in this regard. It is evident that if the least seismic co-efficient for zone III is taken for stability analysis, Mullaperiyar reservoir is not at all safe even to hold water up to the height of 136 ft."
It can be seen that the Central water Commission who should guide the states on safety of Dams is not discharging its responsibilities in public interest on highly scientific lines. For instance, as per international standards, if the historically recorded peak flood in Mullaperiyar in 1943 was 8,453 cumecs, the PMF should have been taken atleast 1.5 times that value and estimated at about 12,680 cumecs or based on the failure of the Machhu Dams in Gujarat PMF value should have been taken at about 17,000 cumecs . Sardar Sarovar dam and Mulla periyar dams are located in the same seismic Zone-III and hence the same seismic coefficients must be applied to ensure safety of the dam.

Hence the views of kerala state are justified and the central government has the responsibility to protect the lives of people downstream the dam.

Sunday, November 27, 2011

Petition Letter
Greetings,
I am writing this letter on behalf of the conscious faction of humanity to warn you about a man-made disaster that's going to happen in Kerala near future and may endanger the lives of 3.5 million innocent people.

The issue is about a DAM by the name ‘MULLAPERIYAR’, which is built over the 'PERIYAR' river in the Idukki district Kerala, India. It was built 115 years back and it's actual expected life was just for 50 years given by its engineers. Moreover, the dam was built with stone and a mixture of sugar and Calcium oxide.. Also the high hazard this dam poses a direct threat to the lives and property of 35 lakhs people living downstream and also a threat to the mega storage Idukki reservoir. Hence Mullaperiyar dam has no parallels and considering its age, deterioration and high hazard nature, must be decommissioned and a new dam must be built.
World over Masonry gravity dams have failed and a few examples are shown below.

A doctoral thesis paper from University of New South Wales, Australia ‘An analysis of Concrete and Masonry Dam Failures’ based on a database called ‘CONGDATA’ is put the figure of the total masonry dam failure reported world over as 21. (This research was funded by the dam’s community in Australia as part of Dam Risk Project, together with ARC and the Faculty of Engineering at the University of New South Wales)
• It reveals that the peaks in failures of masonry gravity dams are noted in dams commissioned in the 1870’s to 1890’s and 1910’s to 1920’s.
• It also reveals that dams within the height range of 15 m to 50 m range are failed more than others.
The above findings are relevant as far as the century old Mullaperiyar Dam concerned because it matches both criteria and the probability of failure of this dam is more compared with others.

Idukki district is prone to heavy earthquakes. Mullaperiyar dam is a composite gravity dam which lost of much of its strength due to continuous leaching of lime from its core. This dam is situated in an active fault zone, which makes the dam vulnerable to failure in an earthquake of moderate intensity with an epicentre close to the dam. The study conducted by IIT Roorkee says that the dam will collapse if an earth quake of magnitude 6 or above occurs. The district was jerked with an earthquake on 26th November, the news link is the reference.
News: http://indiatoday.intoday.in/story/mullaperiyar-dam-site-quake-kerala/1/161725.html
News: http://www.asianetindia.com/news/earthquake-34-magnitude-shakes-idukki_301526.html
The dam is developing new cracks with each earthquake. This area has faced 22 earth quakes so far in this year of 2011. The earthquakes of magnitude 4.5 at Nedumkandam (1988), 4.3 at Wadakkanchery (1994), 5.0 at Periyar basin (2000) and the latest earthquake of magnitudes 3.4 on the Richter scale (18th Nov 2011) at Idukki, clearly justify the views of seismologists that the seismic activity in the regions has recently increased and it is necessary to assess the tectonic behaviour of the region to know the seismic safety of Mulla Periyar, Iddukki and other dams. A study carried out by Indian Institute of Technology, Roorkie, indicates that in the event of an earthquake with a magnitude of 6 on the Richter scale in the vicinity of the dam could wreck the dam. This dam itself holds more than 443.23 million cubic meters of water. If Mullaperiyar dam failed at that time, Idukki dam downstream of Mullaperiyar would have been got overtopped due to the combined storage crossing 70.5 TMC, which Idukki reservoir cannot accommodate in no way. This will also cause the breaking of the smaller downstream Kulamavu dam. Now the dam may collapse anytime, unleashing the most destructive acts of nature. If this event happens, four districts(Idukki, Kottayam, Ernakulam and Alappuzha) will be vanished from the earth and around 3.5 million people will die.

The main problem is, there is no any serious and practical action by our state government or national government or supreme court. The only solution is to make another strong concrete dam parallel to this old dam. Usually it takes too much time for any decisions or order by government and supreme court. There is also an issue with two states about this dam (Kerala and Tamilnadu). That you may please read from Wikipedia page. Of course you can also find many articles about this if you search by keyword "Mullapperiyar" in Google.

Facebook and other social networking websites are being used to mobilise the masses and many people are sharing posts and pages about this to spread the message about the consequences of this unfortunate disaster which is expected to happen in the near future. The people's reaction to the problem is very intense, with frequent strikes. But no solutions till now.

We want to live, We have to save life of our people, children, animal, plants etc.

Actually we don't know what to do. I write to you because, I think, as a normal citizen of my country I have social responsibility to do something as I can.
So, I hope nothing wrong I did here to make you convinced.

So, please talk to the government of India if you have the authority to do so.

Thursday, November 24, 2011

1. We had been hearing about Mullaperiyar issue for quite some time and nothing has happened to it, despite quite a few tremors in the dam site. Is this just a wave of sensation created by media?

Mullapperiyar dam is weak and vulnerable. This has been confirmed by several expert committees. Each tremor , each flood weakens it further. We are just plain lucky that the dam did not fail till today. Lady luck may not be with us forever. It may fail today, it may fail tomorrow. The risk is real. It is not a hoax.

2. What’s wrong with the dam? Why can’t we fix it?
The dam is very old. Not many dams of its age are in service today. The binding material used for the dam is lime. It has leached with age.

3. But Tamil Nadu did some reinforcement in the recent decades.
The reinforcement work did more harm than good to the dam. This has also been confirmed by the experts. There is a horizontal full length crack on the dam, in addition to hollow insides caused by the concreting work, leached lime, breakages and leaks.

4. Isn’t this dam thing a game of mud sling between ruling party and opposition of the State?
No. All political parties of the state stand united, since it is a question of life of millions. They stood so during the previous Government, they continue to do so during the current Government. This is not a political game, this is real.

5. If it is so, why nothing is happening?
It is a complicated legal and political battle between states. Things are before the apex court and it is not so easy to resolve. One state’s demand cannot work out so easily.

6. Mullaperiyar is not that big a dam. It is just 1200 feet long and 150 feet tall. Even if it fails, it may not cause deaths by millions. Especially, considering its immediate flood area is mostly forests.

The disaster will not be just from the failure of one dam. If Mullapperiyar dam breaches, it will discharge millions of cubic feet of waters downstream and Idukki Arch Dam, will not be able to stand even a small portion of it. This will cause failure of Idukki Dam, which will cause of the worst tragedies Kerala has ever known. It is almost certain that Idukki Dam will fail if Mullapperiyar breaches.

7. What would happen if Idukki Dam fails?
The devastating effect of Idukki Dam failure is just unimaginable. Experts say three districts of Kerala will be totally destroyed. Evacuation of people from these three heavily populated districts sensing a dam breach is just impossible.

8. But what would be the impact? If a dam breaches it will be just a flood, right?
Wrong. Idukki dam can discharge 75000 million cubic feet of water. It weighs 22 Billion tons. Dam breaches do not cause just floods. It can even make a landmass disappear instantly. People may die in millions, forests and habitable landscape may get eroded.

9. But Tamil Nadu needs water for irrigation. They are entitled to it by contracts. Why can’t we provide them an alternative source and resolve the issue?
We have already proposed to build a new dam downstream. TN did not agree to it because it will result in new lease agreement and probably new lease rent. It may be a vote wooing tactic for them, but it is a question of life and death for us.

10. What can we do? Can ask our State to forcefully decommission the dam?
Unfortunately, force doesn’t work. If the state decides to take a step that is contradictory to the federal principle, Center will have to intervene. All we can do it so give maximum aware ness to the people , place pressure on Center to take urgent actions and save lives by millions.

11. Which political party should I stand with? Which organization is going to do it right?
All parties stand united for our lives. Support Kerala state, its current ministers, there is no party politics in this. This is a question of survival, there just cannot be two opinion on this. Be part of any party, any campaign, any movement, any activity for it.